Platform stabilizer



June 29, 1965 J. E. WHELAN PLATFORM STABILIZER 2 Sheets-Sheet '1 FiledMarch 6, 1965 H mm W M u mw 1.4 m m a W" m A a 4 J H Y. .5 2 .0. I F

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June 29, 1965 J. E. WHELAN 3,191,895

PLATFORM STABILIZER Filed. March 6, 1963 2 Sheets-Sheet 2 8 INVENTOR.James E Whe/an Fig.6 BY

His Attorney the platform.

United States Patent ice This invention relates to adjustable legs andmore particularly to automatically adjustable legs for stabilizing aplatform or. the like.

One problem with support mounting arrangements for platforms subjectedto dynamic loadings, for example, the platform of an automatic clotheswasher, is that all 20f the supporting legs of the system may not be insolid contact with a supporting surface in cases where the platform isshifted relative to a supporting surface having variances in theelevation thereof or when such a surface settles beneath one or more ofthe legs of the support mounting'arrangernent. Such instability causesthe platform-torock about the legs that are in solid contact with thesurface in an undesirable manner.

Accordingly, objects of the present invention are to provide an improvedplatform stabilizing arrangement;

and to provide such an arrangement including means for continuouslyurging the platform supporting legs into solid contact with a supportingsurface and further including means associated with such legs forresisting cyclical dynamic loading imposed thereon once the legs are insolid contact with the supporting surface.

A further object of the present invention is to provide an improvedplatform stabilizing arrangement having four or more legs supporting aplatform subjected to cyclical dynamic loading with one or more of saidlegs including means for forcing all of the plurality of legs into solidcontact with a supporting surface and further including meansfor'stabilizing the platform against dynamic loading imposed thereononce the legs are in solid contact with the supporting surface.

A still furtherobject is to provide an improved platform stabilizingarrangement that simplifies leveling of Further objects and advantagesof the present invention will be apparent from the followingdescription, reference being had to the accompanying drawings whereinpreferred embodiments of the present invention are clearly shown.

FIGURE 1 is a view in perspective of a platform including the presentinvention;

FIGURE 2 is a view partially in elevation and partially in section ofthe present invention; 7

FIGURE 3 is a view in horizontal section taken on the line-3+3 of FIGURE2;

FIGURE 4 is a fragmentary view in section of a portion of the deviceillustrated in FIGURE 2;

FIGURE 5 is a diagrammatic view of another embodiment of the presentinvention;

platform such as a platform carrying an automatic Washing machine or thelike having adjustable screw legs 12, 14 or the like located on the twofront corners thereof and having a fixed leg 16 and -a stabilizing leg18 embodying one form of the present invention located on the left andright rear corners thereof, respectively. When .the platform is restingon a supporting surface, it will Patented June 29, 1965 be appreciatedthat the legs 12, 14 and 18 can be adjusted relative thereto to assure asolid contact between all four corner support points and the supportingsurface.

The stabilizing leg 18 comprises an extensible piston rod 20 andcylinder 22 with the lower cylinder head 24 of the cylinder 22 having atubular element 26 secured thereon for threadably engaging a screw 28secured to a plate 60 inserted into supporting relationship with aplatform surface engaging foot 32. .The stabilizing leg 18 is secured bya threaded portion 34 on the outer end of the piston rod 21) to suitablyfixed support means 36 on the platform 10 and the opposite end of thepiston rod 20 is directed inwardly of the cylinder 22 through an openingin an upper cylinder head 38 serving as a retainer for O-ring seals 40,41 at the inner and outer peripheries thereof for preventing fluidleakage from the cylinder 22 at the upper end thereof.

The opposite end of the piston rod 20 has a small diameter portion 42formed therein with the shoulders thereof supporting a piston 44, valveplate 46 and retainer element 43 in axial abutment along the outerperiphery thereof. The outer periphery of the piston 44is recessed atSt) for carrying a sleeve-like seal .52 in sealing engagement with theinner surface of the cylinder 22 for forming separate fluid chambers 54,56 within the cylinder 22 on either side of the piston 44. The fluidchambers 54, 56

have a suitable hydraulic fluid 58 therein with the fluid occupying apredetermined portion of the volume of said chambers to permit movementof the piston rod 20 inwardly of the cylinder 22. An arcuate passageway60 ,is directed through the piston 44 for providing fluid communicationbetween the chambers 54, 56 and an arcuate valve seat is formed at 62 onthe lower face of the piston 44 against which the valve plate 46 seatsto prevent fluid flow through the passageway 60 from the fluid chamber56 into the fluid chamber 54 with the valve plate 46 having an arcuategroove 63 formed therein, .as best shown in FIGURE 3, so that the outerperiphery thereof will have suflicient flexibility to quickly move outof engagement with the valve seat 62 to permit free fluid flow from thefluid chamber 54 into the fluid chamber 56 as shown in FIGURE 4. Thepiston 44 further includes a restricted passageway 64 for leakage offluid between the .fluid chambers 54, 56.

In accordance with certain of the principles of the present invention, acoil spring 70 surrounding the lower end of the piston rod 20 has oneend thereof bearing against the lower cylinder head 24 and the oppositeend thereof bearing against the retaining element 48 for biasing the.piston rod 20 and cylinder 22 apart, during which time there is freefluid flow through passageway from chamber 54 to chamber 56, until apredetermined reactive force is imposed on the extensible stabilizingleg 18. Accord- .ingly, in cases where the platform It) is movedrelative .to the supporting surface to cause one of the legs 12, 14, 16to be moved out of solid contact therewith, the spring will cause thestabilizing leg 18 to extend sufficiently to cause all of the legs toagain solidly contact the supporting surface therefor.

Once the legs supporting the platform 10 are all in solid contact withthe supporting surface the valve plate 46 becomes seated on the valveseat 62 to prevent fluid flow from the fluid chamber 56 through thepassageway 60 into thefluid chamber 54. The hydraulic fluid 58 in'thefluid chamber 56 will consequently oppose any cyclical dynamic loadsimposed on the stabilizing leg 18 that might system into solid contactwith the supporting surface therefor and then makes use of the hydraulicfluid therein to prevent collapse thereof when cyclical dynamic loadingor the like is imposed on the platform 10.

The restricted passageway 64 across the piston 44 will, however, permitleakage of fluid from the fluid chamber 56 into the fluid chamber 54when a sustained loading of a predetermined value is imposed on thestabilizing leg as for example when the supporting legs are shifted intoa position Where the leg 18 must retract a predetermined distance inorder to again obtain solid contact between the legs and the supportingsurface. In this case, a disproportionate portion of the weight of theplatform is imposed on the leg 18 and the fluid in the chamber 56 isthereby forced across the restricted passageway 64 into the chamber 54until the platform is again in a stable position.

Another advantage of the present invention is that it enables a platformto be quickly leveled since adjustment of the screw leg locateddiagonally of the stabilizing leg 18 will level the platform along thediagonal line therebetween without having to take up or extend the leg18. More particularly, in the ilustrated arrangement, the stabilizingleg 18 is associated With a fixed leg 16 on the rear of the platform andadjustable legs 12, 14 on the front of the platform and the length ofthe fixed leg 16 may be approximately at the midstroke of thestabilizing leg 18 and the midpoint of the adjustment range of thescrewtype legs 12 and 14. This arrangement enables the platform to belocated in an alcove or the like as a built-in type fixture where therear legs are relatively inaccessible. If all of the legs are of thescrew adjustable type, it is difficult to take up and extend the legs onthe back of a platform so situated during leveling thereof. Theprovision of the improved stabilizing leg 18 in the described supportmounting system, however, is such that the platform 10 can be leveled bymerely adjusting the screw legs 12, 14 on the front thereof withouthaving to take up or extend the supporting legs on the rear of theplatform. This obviously enables the platform 10 to be leveled veryquickly with a minimum of effort even though it is part of a builtintype fixture. Such improved leveling is also possible when any of thestabilizing arrangements to be discussed are employed in a supportmounting system.

FIGURE illustrates another stabilizing leg arrangement 8t) constructedin accordance with the principles of the present invention to include anextensible cylinder 82 and piston rod 84 with the upper head 86 of thecylinder 82 being adapted to be connected to means for securing thestabilizing leg 80 to a platform having legs such as those illustratedin FIGURE 1 and with the piston rod having a threaded tubular portion 87on the outer end thereof adapted to be connected to suitable means suchas the foot 32 in the embodiment of FIG- URE 2 for supporting the leg 80on a platform supporting surface. The opposite end of the piston rod 84is connected to a first piston 88 having an O-ring seal 90 located inthe outer periphery thereof in sealing engagement with the inner surfaceof the cylinder 82 for forming a first fluid chamber 92 in the upper endof the cylinder. A second fluid chamber 94 is formed on the oppositeface of the first piston 88 by the cylinder 82 and a second piston 96slidably carried on the outer periphery of the piston rod 84 andincluding O-ring seals 98 and 100 in the outer and inner peripheriesthereof, respectively, for preventing fluid leakage thereacross.

The fluid chambers 92, 94 have a suitable hydraulic fluid 102 thereinand the first piston 88 has a passageway 184 directed therethrough forallowing fluid flow thereacross, under the control of a one-way checkvalve 105 located therein. A spring 106 is located between a portion onthe lower end of the cylinder 82 directed inwardly toward the rod 84 andthe lower surface of the second piston 96 for moving the second piston96 relative to the first piston 88 to compensate for movement of thepiston rod 84 into and out of the fluid chamber 94 during the operationof the stabilizing leg 80.

As was the case in the first embodiment, this arrangement of theinvention includes a spring 107 mounted within the fluid chamber 92between the upper cylinder head and the upper face of the first piston88 for moving the first piston 88 relative to the cylinder 82 forobtaining solid contact between legs such as those illustrated in thefirst embodiment and a surface for supporting a platform connectedthereto as previously discussed. When the piston rod 84 is extendedoutwardly of the cylinder 82 by the spring 107 there is an unrestrictedflow of fluid from the chamber 94 to the chamber 92 and as was the casein the first embodiment, the stabilizing leg will then be maintained insolid contact with a supporting surface by the hydraulic fluid 102 inthe fluid chamber 92. A restricted passageway 108 is directed throughthe first piston 88 for permitting leakage from the fluid chamber 92into the fluid chamber 94 when a sustained force is imposed on the legas for example when the support mounting system including thestabilizing leg 80 is shifted into a new position where the stabilizingleg 80 must retract to obtain a stable platform as discussed in thefirst embodiment.

Another arrangement of the invention is illustrated in FIGURE 6 asincluding a stabilizing leg 110 comprising an extensible cylinder 112and piston rod 114 with the upper head of the cylinder 112 adapted to beconnected to means for securing the leg 110 to a platform having legssuch as those illustrated in FIGURE 1. One end of the piston rod 114 isdirected outwardly of the cylinder 112 and is adapted to carry a pad orfoot such as the foot 32 in the embodiment of FIGURE 1 and the oppositeend of the piston rod 114 is connected to a first piston 116 slidablymounted Within the cylinder 112 at the lower end thereof and having anO-ring seal 118 in the outer periphery thereof for sealing against fluidleakage from the cylinder 112 across the piston 116.

The arrangement of FIGURE 6 further comprises a wall 120 formed in thecylinder 112 transversely thereof to form a first fluid chamber 122 inthe cylinder 112 above the upper face of the piston 116. A second fluidchamber 124 is formed on the opposite side of the wall 120 by thecylinder 112 and a second piston 126 having an O- ring seal 128 in theouter periphery thereof slidably engaging the inner surface of thecylinder 112 for preventing fluid leakage from the cylinder 112 acrossthe piston 126. The fluid chambers 122, 124 have a suitable hydraulicfluid 130 therein and the wall 120 has a passageway 132 directedtherethrough for providing fluid communication between the fluidchambers 122, 124 under the control of a one-way check valve 134 locatedwithin the passageway 132.

As was the case in the previous embodiments, a spring 136 is locatedwithin the cylinder 112 between the upper head thereof and the upperface of the second piston 126 for biasing the second piston 126downwardly to cause unrestricted fluid flow from the fluid chamber 124through the passageway 132 into the second fluid chamber 122. Thiscauses movement of the first piston 116 outwardly of the cylinder 112until all of the legs of the platform mounting system associated withthe stabilizing leg 110 are in solid contact with the supportingsurface. Once the legs are in such solid contact the one-way check valve134 will prevent fluid flow from the fluid chamber 122 into the fluidchamber 124 and the hydraulic fluid 130 within the fiuid chamber 122will effectively resist cyclical dynamic loading imposed upon theplatform mounting system that might cause the stabilizing leg 110 tocollapse. As was the case in the previous embodiments, a restrictedpassageway 138 is directed through the wall 120 to provide for leakageof fluid between the fluid chambers 122, 124 when a sustained loading ofa predetermined value is imposed onthe leg 110.

Another arrangement of the present invention is illustrated in FIGURE 7as including a stabilizing leg 140 comprising an extensible cylinder 142and piston rod 144 with the upper cylinderrhead of the cylinder 142again being adapted to be connected to means for securing thestabilizing leg 140 to a platform having a plurality of legs asdiscussed above. One end of the piston rod 144 is directed outwardly ofthe cylinder 142 and includes a threaded tubular portion 146 adapted tocarry a pad or foot for engaging a supporting surface for the platformand the opposite end thereof is directed through the upper head of thecylinder for supporting a piston 148 secured intermediate the endsthereof within the cylinder 142. Suitable O-ring seals 150, 152 aremounted within the upper and lower cylinder heads of the cylinder 142,respectively, for preventing fluid leakage outwardly of the cylinder 142along the outer periphery of the piston rod 144 and the piston 148 hasan Oring seal 154 located in the outer periphery thereof engaging theinner surface of the cylinder 142 for preventing leakage across theouter periphery thereof between fluid chambers 156, 158 formed in thecylinder 142 on either side of the piston 148. A suitable hydraulicfluid 160 fills the chambers 156, 158. A passageway 162 is directedthrough the piston 148 for providing fluid communication between thefluid chambers 156, 158 under the control of a one-way check valve 163located therein. In this arrangement extension of the stabilizing leg140 is produced by means of a spring 164 mounted within the fluidchamber .158 having one end thereof engaging the upper cylinder head andthe opposite end thereof engaging the upper face of the piston 148 tobias the cylinder 142 and piston 148 apart. The one-way check valve 163is arranged to allow free fluid flow from the fluid chamber 156 to thefluid chamber 158 on such extension but will prevent fluid flowtherebetween once the legs have been moved into solid contact asdiscussed above so that the hydraulic fluid 160 within the fluid chamber158 'will opposed dynamic loading imposed on the support mounting systemthat might tend to collapse the stabilizing leg 140. A restrictedpassageway 166 is, however, provided across the piston 148 for allowingleakage thereacross to stabilize the system when a predeterminedsustained loading is imposed on the stabilizing leg 140.

Yet another arrangement of the present invention is illustrated inFIGURE 8 as including a stabilizing leg 170 comprising an extensiblecylinder 172 and piston rod 174 with the upper head of the cylinder 172again being adapted to be connected to means for securing thestabilizing leg 170 in a platform supporting system. One

end of the piston rod 174 is directed outwardly of the cylinder 172 andhas a tubular threaded portion 176 adapted to carry a pad or a foot forengaging a platform supporting surface and the opposite end of thepiston rod 174 is located within the cylinder 172 and connected to apiston 178 having an O-ring seal 180 in the outer periphery thereofslidably engaging the inner surface of the cylinder 172 for preventingfluid leakage from the cylinder 172 across the piston 178. In thisarrangement the cylinder 172 is divided into two parts by a wall 182directed thereacross intermediate the ends thereof with the wall 182 andthe upper face of the piston 178 forming a first fluid chamber 184within the cylinder 172 separated by the wall 182 from a second fluidchamber 186 formed in the cylinder 172 above the wall 182. A suitablehydraulic fluid 188 in the fluid chambers 184, 186 flows through apassageway 190 directed through the wall 182 under the control of aone-way check valve 192.

In this arrangement the stabilizing leg 170 is adjusted into solidcontacting relationship with a platform supporting surface by means of aspring 194 mounted within the first fluid chamber 184 having one endthereof bearing against the upper surface of the piston 178 and theopposite end thereof engaging the wall 182 for biasing the piston 178 ina direction to cause the piston rod 174 to move outwardly of thecylinder 172 during which time there is a free flow of fluid from thefluid chamber 186 through the passageway 190 into the fluid chamber 184.Once the stabilizing leg is in solid contact with the supporting surfacethe fluid drawn into the fluid chamber 184 by. the outward extension ofthe piston 178 is trapped thereinby the one-way check valve 192 tooppose cyclical dynamic loading transmitted to the stabilizing leg 170through the platform mounting system so as to prevent the collapsethereof. A restricted passageway 196- extends through the wall 182allowing controlled leakage between the fluid chambers 184, 186 when asustained force is imposed thereon under conditions discussed above.

While the embodiments of the present invention as herein disclosedconstitute preferred forms, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. A stabilizing leg comprising a cylinder, a first piston mountedwithin said cylinder, a second piston mounted within said cylinder, saidfirst and second pistons and said cylinder forming separate chambershaving an incompressible fluid therein, spring means within saidcylinder for biasing said second piston in a first direction relative tosaid cylinder, control means permitting free flow of fluid between saidchambers upon movement of said second piston in said first direction forcausing a first predetermined relative movement between said cylinderand said first piston, said control means restricting fluid flow betweensaid chambers upon relative movement between said first piston and saidcylinder opposite to said first predetermined relative movement forcausing fluid in one of said chambers to oppose such opposite movement.

2. A stabilizing leg for leveling a domestic appliance comprising, acylinder, a piston mounted for reciprocation in said cylinder, a pistonrod connected to said piston directed exteriorly of said cylinder, saidcylinder and piston forming separate chambers having an incompressiblefluid therein, a compression spring in one of said chambers for biasingsaid piston in a first predetermined direction to move said piston rodexteriorly of said cylinder, passageway means in said piston, one-wayvalve means for opening said passaageway means upon movement of saidpiston in said first predetermined direction, said valve means operativeto close said passageway means upon movement of said piston opposite tosaid first predetermined direction, and means in said piston forrestricing fluid flow upon said opposite movement whereby saidincompressible fluid serves as a hydraulic support when said leg is in apredetermined relationship with respect to the domestic appliance.

3. In the combination of claim 2, said piston including means on oneface thereof forming a valve seat, said oneway valve means being a discvalve connected to said piston adjacent said one face and biased intosealing engagement with said valve seat to prevent flow through saidpiston passageway means upon movement in said first predetermineddirection.

4. In the combination of claim 3, said disc valve having a radiallyinwardly located arcuate groove for causing the outer peripheral edge ofsaid disc valve to have a high flexibility whereby said disc valvequickly responds to movement of said piston in said predetermineddirection to allow free fluid flow through said piston passageway means.

5. A stabilizing leg for leveling a domestic appliance comprising, ahollow cylinder having oppositely closed ends, a piston mounted forreciprocation within said cylinder, a thin annular relativelyfrictionless bearing member supported in the outer periphery of saidpiston, said bearing member slidably sealingly engaging the inner Wallof said cylinder, said cylinder and piston forming separate chambers oneither side of said piston having an incompressible fluid therein, apiston rod having one end thereof secured to one face of said piston andthe opposite end thereof directed exteriorly of said cylinder throughone of the closed ends thereof for connection to the frame of a domesticappliance, a compression spring located in one of said separate chambersfor moving said piston in a direction to cause said piston rod to moveexteriorly of said cylinder, passageway means through said piston forfluidly communicating said separate chambers, valve means carried bysaid reciprocal piston and piston rod including means for opening saidfluid piston passageway means upon movement of said piston rodexteriorly of said cylinder, said valve means being operative to closesaid piston passageway means upon movement of said piston rod into saidcylinder.

References Cited by the Examiner UNITED STATES PATENTS FRANK L. ABBOTT,Primary Examiner.

2. A STABILIZING LEG FOR LEVELING A DOMESTIC APPLIANCE COMPRISING, ACYLINDER, A PISTON MOUNTED FOR RECIPROCATION IN SAID CYLINDER, A PISTONROD CONNECTED TO SAID PISTON DIRECTED EXTERIORLY OF SAID CYLINDER, SAIDCYLINDER AND PISTON FORMING SEPARATE CHAMBERS HAVING AN IMCOMPRESSIBLEFLUID THEREIN, A COMPRESSION SPRING IN ONE OF SAID CHAMBERS FOR BIASINGSAID PISTON IN A FIRST PREDETERMINED DIRECTION TO MOVE SAID PISTON RODEXTERIORLY OF SAID CYLINDER, PASSAGEWAY MEANS IN SAID PISTON, ONE-WAYVALVE MEANS FOR OPENING SAID PASSAGEWAY MEANS UPON MOVEMENT OF SAIDPISTON IN SAID FIRST PREDETERMINED DIRECTION, SAID VALVE MEANS OPERATIVETO CLOSE SAID PASSAGEWAY MEANS UPON MOVEMENT OF SAID PISTON OPPOSITE TOSAID FIRST PREDETERMINED DIRECTION. AND MEANS IS SAID PISTON FORRESTRICING FLUID FLOW UPON SAID OPPOSITE MOVEMENT WHEREBY SAIDINCOMPRESSIBLE FLUID